Understanding Effects of Communicating Different Types of Conflicting Information About Nutrition and Cancer Risk

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Principal investigators:

Irina Iles

National Cancer Institute

Email: irina.iles@gmail.com

Arielle S. Gilman

National Cancer Institute

Email: arielle.gillman@nih.gov

Lauren O'Connor

National Cancer Institute

Email: lauren.oconnor@nih.gov

Rebecca Ferrer

National Cancer Institute

Email: rebecca.ferrer@nih.gov

William Klein

National Cancer Institute

Email: kleinwm@mail.nih.gov

Sample size: 1027

Field period: 12/10/2020-05/06/2021

H1. Consistent with previous research, we hypothesized that exposure to any conflicting information (vs. control), as well as exposure to each conflicting information type (vs. control), will lead to higher nutrition confusion (i.e., higher confusion about nutrition recommendations, lower perceptions of scientific consensus about the amount of red meat one should consume; higher cancer fatalism), higher negative affective reactions, lower trust in scientists, and lower intentions to follow (topic-related and topic-unrelated) public health recommendations.

H2. Because people prefer conflict in evidence vs. conflict between sources about the evidence (Smithson, 1999), we hypothesized that exposure to conflict between sources (vs. conflict in evidence) will lead to higher confusion, higher negative affective reactions, lower trust in scientists, and lower intentions to follow (topic-related and topic-unrelated) public health recommendations.

RQ1. We further explored whether a public health organization changing its own recommendation (vs. conflict between sources and conflict in evidence) had different effects on confusion, affective reactions, trust, and behavioral intentions.

RQ2. As a sensitivity analysis, we also examined if the above comparisons were significantly modified by the direction of the initial recommendation to parse whether it was exposure to conflicting information that caused reactance or only conflicting information that suggested a behavior change.

Participants first rated on a 7-point Likert scale several items that captured confusion regarding the state of science on nutrition and cancer: 1) confusion about nutrition recommendations (six items; e.g., It is not always clear to me what food are best to eat; α=0.76) (Nagler, 2014); 2) perception of the scientific consensus about the amount of red meat they should consume (one item: “The scientific community is in agreement about the amount of red meat you should consume.”) (Cook et al., 2017); and 3) cancer fatalism (one item: “There’s not much you can do to lower your chances of getting cancer.”) (National Cancer Institute, 2008).

Next, participants reported affective reactions by rating on a 5-point scale how much of three negative emotions (frustrated/annoyed/distressed) they felt as a result of the article they read (α=0.85) (Nagler et al., 2019).

Next, participants reported their trust in scientists or science experts by rating four adjective pairs on a 7-point scale (non-collaborative/collaborative; incompetent/competent; untrustworthy/trustworthy; not protective of public interest/protective of public interest) (α=0.86) (Jensen & Hurley, 2012).

Finally, participants reported their intentions to follow (topic-related and unrelated) public health recommendations: plans about red meat in their diet over the next month (1 – eat a lot less to 7 – eat a lot more; and 8 – “I don’t eat red meat now and will not eat red meat in the future”) and how likely they were to have five or more servings of fruits and vegetables most days in the next month (5-point scale) (Nagler, 2014).